Binary Mixed Homopolymer Brushes Tethered to Cellulose Nanocrystals: A Step Towards Compatibilized Polyester Blends

Abstract

This article reports on the successful preparation and characterization of cellulose nanocrystals (CNCs) surface-modified with polylactide (PLA) and poly­(butylene succinate) (PBS) binary mixed homopolymer brushes. Their synthesis was designed as a three-step procedure combining polyester synthesis and surface-modification of CNCs with simultaneous polyester grafting via a heterogeneous copper­(I)-catalyzed azide–alkyne cycloaddition reaction. For comparison, single homopolymer brushes tethered to CNCs (PLLA-g-CNC and PBSBDEMPAM-g-CNC) were obtained applying the same procedure. The hairy nanoparticles were characterized in terms of chemical composition and thermal properties. Spectroscopic analyses suggested “rippled” microphase separation of both immiscible homopolyesters in the mixed brushes, while others showed impeded homopolyester crystallization after surface-grafting. A synergistic relationship between the polyesters and CNCs was also suggested, i.e., the polyester grafting increases the CNC thermal resistance, while CNC presence imparts char formation. The as-obtained binary homopolymer brushes tethered to nanoparticles makes these surface-modified cellulosic nanomaterials attractive as compatibilization/reinforcement agents for PLA/PBS blends.

Regiocontroll synthesis cellulose-graft-polycaprolactone copolymer (2,3-di-O-PCL-cellulose) by a new route

“…In the esterification reaction, the reactivity of primary hydroxyl is higher than that of the secondary hydroxyl because of the steric hindrance of primary hydroxyl. And in the acidic medium, the reaction on the primary hydroxyl is even easier [35]. And a preferential reaction is at the C 6 position of cellulose, and the order of reactivity is C 6 -OH > C 3 -OH > C 2 -OH which is well consistent with the reported work for cellulose graft in ionic liquid [31,32].…”

“…This hypothesis is interesting and exciting, the method is new and special. The cellulose derivatives with different groups have a good chance in many fields such as medicine, food packaging, polymer chemistry and polymer processing and so on [22,23,35,36]. So, the further work will be focused on above feasibility to synthesize functional cellulose derivatives.…”

Advanced Materials through Assembly of Nanocelluloses

“…The dual responsiveness of CNC‐ g ‐PDMAEMA and other polymers has further been used to tune the stabilizing effect of colloidal surfactants in Pickering emulsions . Colloidal particles are particularly effective to stabilize interfaces and polymer‐grafted CNCs may find application as emulsifiers in emulsion polymerization or as compatibilizers in polymer blends, as suggested also related findings using carbon nanotubes . Also more advanced copolymer brushes have been presented with host guest functionalities and supramolecular bonding motifs in order to generate sophisticated fracture behavior, which will be discussed in more detail in Section .…”

Preparation and characterization of air nanofilters based on cellulose nanofibers

“…In this study, the peaks around 1314 and 1430 cm −1 in both the unmodified and modified CNF spectra could be assigned to the symmetric bending of CH 2 and the bending vibrations of the C\ \H and C\ \O groups of the rings in polysaccharides, respectively. Furthermore, the absorbance peaks in the range 1162-1030 cm −1 are attributed to C\ \O stretching and C\ \H rocking vibrations of the pyranose ring skeleton and the bands in the range 1000-1200 cm −1 are assigned to the carbohydrate rings of the cellulose skeleton [15,32]. The vibration peak at 900-895 cm −1 in the spectra which are symmetric in polysaccharides is usually assigned to the glycoside bonds, represents the βglucosidic linkage between glucose units in cellulose [15,33,34].…”